    #ifdef UNMANAGED_EXPORTS
    #define UNMANAGED_API __declspec(dllexport)
    #else
    #define UNMANAGED_API __declspec(dllimport)
    #endif
struct MyStruct
{
      int       SomeId;
      double SomePrice;
};

extern "C" __declspec(dllexport) void PassStructIn(MyStruct* myStruct);    